Bravo I Trim Issues - Ideas?
10-05-2004, 04:01 PM
#1
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Thread Starter
Bravo I Trim Issues - Ideas?
Wondering what anybody's ideas might be on this. Running a 26 ft Wellcraft Nova with a Bravo I, mildly blown 454, and a 23 pitch 3-blade. When I hammer it out of the hole, it goes for a short period and then feels like I have a cavitation issue. If I baby it up until it's on plane, no problems. My trim must have slight leak as the outdrive requires fairly regular adjustments and the trim will "sag" if it sits on the trailer for a few days.
My question, is this a cavitation issue with the prop or is my trim pump not strong enough to keep the outdrive down in the water? I think it's the latter because when this "blow-out" occurs, I've noticed a little rooster tail from the prop angling upward.
Has anyone experienced something like this? Would a new trim pump fix it? Thanks in advance.
SM
My question, is this a cavitation issue with the prop or is my trim pump not strong enough to keep the outdrive down in the water? I think it's the latter because when this "blow-out" occurs, I've noticed a little rooster tail from the prop angling upward.
Has anyone experienced something like this? Would a new trim pump fix it? Thanks in advance.
SM
10-06-2004, 01:50 PM
#4
Re: Bravo I Trim Issues - Ideas?
The forward spiining motion of the prop will be forcing water backwards, thus propelling your drive further "IN" not "OUT". If anything it will force the drive inward.
How long have you have the blower setup? sounds like that prop is too small for the boat. My old boat was 25' with mild blower and i was spinning a 27 pitch 4 blade.
How long have you have the blower setup? sounds like that prop is too small for the boat. My old boat was 25' with mild blower and i was spinning a 27 pitch 4 blade.
10-12-2004, 03:19 PM
#6
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Thread Starter
Re: Bravo I Trim Issues - Ideas?
Originally Posted by hi-perf-2000
The forward spiining motion of the prop will be forcing water backwards, thus propelling your drive further "IN" not "OUT". If anything it will force the drive inward.
How long have you have the blower setup? sounds like that prop is too small for the boat. My old boat was 25' with mild blower and i was spinning a 27 pitch 4 blade.
How long have you have the blower setup? sounds like that prop is too small for the boat. My old boat was 25' with mild blower and i was spinning a 27 pitch 4 blade.
Thanks for the ideas, guys. I bought the boat with this set-up, but it sure sounds like a 4-blade might be the way to go.
I've also been reading up on the removal of the "exhaust bellow" on a Silent Choice set-up. Anybody familiar with this? Thanks again. SM
10-13-2004, 12:43 AM
#7
Re: Bravo I Trim Issues - Ideas?
the exhaust bellow should be removed on thru transom and silent chioce boats. it can actually create a slight vacume in the drive and thus the prop the can cuase cavition although i don think this is the problem in your case i think you just dont have enough prop and a 4 blade like a B-1 would be a good starting point for testing. most dealers will allow you to return an undamaged and factory packaged prop in exchange for another one so you can find out waht works best without buying 20 props. I think a 24 or 26 pitch would be the place to start for you.
